That's how many rushing yards the Seahawks gained in Minnesota, dipping below the low-water mark in franchise history set just five weeks earlier against Arizona. But that game against the Cardinals was different. The Seahawks were playing with Kyle Williams, their fourth starting left tackle of the season, and Steve Vallos, their third different left guard.

Sunday was different. This was purportedly Seattle's first-string line that wasn't even slightly bothersome to the Vikings' defensive line. Sure, that's a pretty good line, probably even great, but the Vikings have played nine other games this season and they haven't held any other opponent to fewer than 50 yards rushing. Cleveland rushed for 89 yards against the Vikes. Detroit ran for 129.

Four yards? You can get that falling down a couple of times, right? Well, not if there's no room to fall forward, and the fact Seattle was so utterly and completely incapable of moving forward puts a spotlight on one of the most pressing personnel questions facing this team.

How do you fix the offensive line?

It's not the position coach. Offensive-line coach Mike Solari is considered one of the best in the business. It's not the scheme. The zone-blocking system installed over the offseason has a lineage of success that includes Mike Shanahan's back-to-back Super Bowls in Denver.

Seattle has faced unique challenges in terms of personnel. In 10 games this season, the Seahawks have started four different left tackles and three left guards, and none of those seven players were the two players projected as starters over the offseason. Tackle Walter Jones and guard Mike Wahle didn't play so much as a single snap in the regular season.

But this isn't a matter of waiting to get healthy. Wahle is gone and Seattle can't rely upon Jones coming back. It must plan for the worst-case contingency that he won't be back.

So where does Seattle go from here? Not very far, judging by Sunday's results.

With six games left in the season, Seattle faces questions up front. Center Chris Spencer is in his fifth year and courageously playing with a broken right thumb, but he struggled Sunday in Minnesota. He's a free agent after this season. So is left guard Rob Sims, who graded out well the past few games, but can he be a building block for the future?

These are evaluations Seattle's front office must make. The lineman who has shown the most promise this season is rookie Max Unger, who is playing right guard but was drafted to play center.

Then there's Sean Locklear, who was re-signed in 2008 with the idea that he could be the eventual successor to Jones at left tackle. Of course, that succession plan was not revealed until more than a year after Locklear re-signed.

Seattle has not drafted a person to play tackle since choosing Ray Willis in the fourth round of the 2005 draft, resulting in a lack of depth at that position exposed so glaringly this season. Seattle has started a player signed one week before the regular season began (Brandon Frye) and one signed in the middle of the season (Damion McIntosh). Both played left tackle, and if a team can just go sign one off the street the whole NFL salary structure is off-base.

President Tim Ruskell does not have a track record of choosing offensive linemen high in the draft. Since he was promoted to Tampa Bay's director of college scouting in 1992, Ruskell's team has chosen just two offensive linemen in the first round. The Bucs picked Kenyatta Walker No. 14 overall in 2001, and the Seahawks chose Spencer 26th in 2005.

Now, Seattle has two first-round choices this season and a glaring question along its front line. Back in 2005, the offensive line was the signature of this Seahawks team, clearing the way for the franchise's first Super Bowl appearance.

But the line that was once Seattle's identity is now in the midst of an identity crisis.

Danny O'Neil will comment on issues, events and personalities in the NFL. His column will appear on Sundays during the regular season. He also posts most days on the Seahawks Blog.doneil@seattletimes.com| 206-464-2364